aliases / specify model+reasoning combinations once / local XDG settings not read

Because different contributors to open source projects have different model credentials and different (possibly local) capabilities, the project's model settings, including reasoning.effort, must be overridden locally. Model aliases provide some but not all of this functionality.

It is possible to specify anything on the command line, but local config files should handle this.

Does config_load_paths operate in XDG/config.toml? Does setting it allow mirroring the project persona hierarchy with XDG persona patches, so that -c dev loads from the project dev.toml persona as well as the XDG-path dev.toml persona? It seems not. This does not seem like a favorable solution in any case, as locally mirroring the project personas sounds fragile.

I think JP's current theory would like me to use a local-to-machine-and-project config.toml. However, model availability comes and goes frequently, and I want to name model+reasoning combinations once, not duplicate this configuration task around in dozens of different project files, with some always out of date.

Start by tracing config_load_paths and how XDG/config.toml, project config.toml, persona patches, and the -c dev selection are resolved. Clarify whether local settings can override model and reasoning.effort combinations without duplicating project personas. Done should be a concrete, documented configuration behavior that supports the requested local overrides.